This invention relates to light reflectors and in particular to a reflector system which when used in connection with an elongated light source modifies the light intensity distribution pattern of the light source to conform to a desired pattern.
A high intensity tubular shaped lamp has characteristic light intensity distribution patterns. In particular the pattern in the vertical direction, i.e., in a plane that is perpendicular to the long axis of the lamp, is constant with respect to the angle of rotation in the plane. However, the pattern in the horizontal direction, i.e., in a plane that is parallel to the long axis of the lamp, varies with the angle of rotation in that plane in accordance with the relationship: EQU I(.phi.)=I.sub.0 cos(.phi.) Eq. (1).
It is difficult, if not impossible, to increase the horizontal light distribution pattern near the ends of such a lamp (.phi.=90.degree.) solely by use of a refractive lens.
Such high intensity lamps are used in visual warning systems, a particular example being smoke alarms for persons with impaired hearing. Those units include a high intensity flash lamp to provide a visual alarm. Recent requirements for the light intensity distribution pattern in the horizontal direction, also known as the horizontal roll-off characteristic, for such devices, have created a genuine need for an effective means to modify the horizontal roll-off characteristic of the flash lamp in order to meet the current specification.